Importer: Add a RemoveObserver method to ImporterList and use this method by

clients when they are destroyed.

BUG=67174
TEST=none

Review URL: http://codereview.chromium.org/6409028

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@73233 0039d316-1c4b-4281-b951-d872f2087c98

5 files changed, 21 insertions, 3 deletions

diff --git a/chrome/browser/dom_ui/options/import_data_handler.cc b/chrome/browser/dom_ui/options/import_data_handler.cc
index ee07b48..4db124d 100644
--- a/chrome/browser/dom_ui/options/import_data_handler.cc
+++ b/chrome/browser/dom_ui/options/import_data_handler.cc
@@ -25,6 +25,9 @@ ImportDataHandler::ImportDataHandler() : importer_host_(NULL) {
 }
 
 ImportDataHandler::~ImportDataHandler() {
+  if (importer_list_)
+    importer_list_->SetObserver(NULL);
+
   if (importer_host_)
     importer_host_->SetObserver(NULL);
 }
diff --git a/chrome/browser/dom_ui/options/import_data_handler.h b/chrome/browser/dom_ui/options/import_data_handler.h
index 8f4ed61..4ba21b6 100644
--- a/chrome/browser/dom_ui/options/import_data_handler.h
+++ b/chrome/browser/dom_ui/options/import_data_handler.h
@@ -39,7 +39,7 @@ class ImportDataHandler : public OptionsPageUIHandler,
   scoped_refptr<ImporterList> importer_list_;
 
   // If non-null it means importing is in progress. ImporterHost takes care
-  // of deleting itself when done import.
+  // of deleting itself when import is complete.
   ImporterHost* importer_host_;  // weak
 
   DISALLOW_COPY_AND_ASSIGN(ImportDataHandler);
diff --git a/chrome/browser/importer/importer.cc b/chrome/browser/importer/importer.cc
index e1483ba..bb3b237 100644
--- a/chrome/browser/importer/importer.cc
+++ b/chrome/browser/importer/importer.cc
@@ -108,8 +108,11 @@ ImporterHost::ImporterHost(ImporterList::Observer* observer)
 }
 
 ImporterHost::~ImporterHost() {
+  importer_list_->SetObserver(NULL);
+
   if (NULL != importer_)
     importer_->Release();
+
   if (installed_bookmark_observer_) {
     DCHECK(profile_);  // Only way for waiting_for_bookmarkbar_model_ to be true
                        // is if we have a profile.
diff --git a/chrome/browser/importer/importer_list.cc b/chrome/browser/importer/importer_list.cc
index a6c85d1..80b1e84 100644
--- a/chrome/browser/importer/importer_list.cc
+++ b/chrome/browser/importer/importer_list.cc
@@ -164,6 +164,10 @@ void ImporterList::DetectSourceProfiles(Observer* observer) {
       NewRunnableMethod(this, &ImporterList::DetectSourceProfilesWorker));
 }
 
+void ImporterList::SetObserver(Observer* observer) {
+  observer_ = observer;
+}
+
 void ImporterList::DetectSourceProfilesHack() {
   DetectSourceProfilesWorker();
 }
@@ -258,7 +262,10 @@ void ImporterList::SourceProfilesLoaded(
 
   source_profiles_->assign(profiles.begin(), profiles.end());
   source_profiles_loaded_ = true;
-  observer_->SourceProfilesLoaded();
-  observer_ = NULL;
   source_thread_id_ = BrowserThread::UI;
+
+  if (observer_) {
+    observer_->SourceProfilesLoaded();
+    observer_ = NULL;
+  }
 }
diff --git a/chrome/browser/importer/importer_list.h b/chrome/browser/importer/importer_list.h
index 513a55f..17dbc41 100644
--- a/chrome/browser/importer/importer_list.h
+++ b/chrome/browser/importer/importer_list.h
@@ -41,6 +41,11 @@ class ImporterList : public base::RefCountedThreadSafe<ImporterList> {
   // non-NULL.
   void DetectSourceProfiles(Observer* observer);
 
+  // Sets the observer of this object. When the current observer is destroyed,
+  // this method should be called with a NULL |observer| so it is not notified
+  // after destruction.
+  void SetObserver(Observer* observer);
+
   // DEPRECATED: This method is synchronous and performs file operations which
   // may end up blocking the current thread, which is usually the UI thread.
   void DetectSourceProfilesHack();